4wsB21a

in another forum someone posted that (for example) when my crx hits 7200 rpms it hits the fuel cut-off, the fuel is leaned out, and the engine can be damaged. it was also stated that most hondas have either a 6100 rpm rev limiter or 6800 rpm rev limiter, or somewhere between the two.

i thought the rev limiter was when the car hit (for example) 7200 rpms and shut the fuel off. that rev limiter is the "safe" point for the car in stock form. and that is what the rev limiter is for. does it hurt the car to hit the rev limiter? if that is not the rev limiter, then how do you know when you hit it?

Stephen

Its not really a rev limiter, per se. Its a fuel cutoff. You can rev past this point if you mis-shift...it is possible to rev to 10,000 rpm...your motor won't get fuel, but there's nothing preventing you from spinning the motor that fast...a true rev limiter would prevent something like this. Anyway, after you hit the fuel cut, you're running your motor without fuel. Gas/air is going through the cylinders but not detonating, which in itself is not a biggie. The big deal is that your motor isn't firing, and this happens abruptly. When you're at the cutoff point, your engine continuously cuts on and off, sending inconsistent vibrations through the whole system. It continuously starts/stops at high RPM...this is not really good for it.

rainforest

you can get a spark cut from msd it comes on the msd's ignition systems.

Jesse H

impossible to have a "true rev limiter" whether it be fuel or spark.

say you're going 70 in 5th and downshift to 2nd. No fuel or spark cut is going to prevent the crank from spinning past it's intended redline.

Crazydave

well... when your bearings fail.. and your rod goes through the block/oil pan or other bottom end parts break... you'll quickly learn to not mis-shift

4wsB21a

so basically there is no such thing as a rev limiter? the only thing that stops the engine from going past a certain rpm is the fuel cut-off (unless of course you do the miss shift). so how can anyone say there is a rev limiter on a car?

XES

The spark cut is definately safer than the fuel cut (obviously), i.e. like an MSD. On missed shifts the only way to stop an overreving condition would be to have a break on the crank. Anyways, if you have a well build top and bottom end the over-rev won't do that much damage (when my ignition cut was 8200, I frequently over-reved past 9000 rpm). The only thing I ever had to do was tighten up the valvetrain. No biggie.

Go ignition cut.

--------------------------
XES
non-na


[Modified by XES, 2:19 PM 2/4/2002]

Lt. Dan

over rev a honda four cylinder, 9 times out of ten, you're gonna bed a valve... plain and simple.

Dan